The statements in this section merely provide background information related to the present disclosure. Accordingly, such statements are not intended to constitute an admission of prior art.
Fuel systems supply fuel to internal combustion engines. One known fuel system includes a fuel pump and electric motor that are submerged in a fuel tank. A fuel filter and a pressure regulator may be positioned on the intake and outlet sides of the fuel pump, respectively. Filtered fuel is delivered to a fuel rail for injection into the engine cylinders. One embodiment of a fuel system includes a returnless fuel system that is assembled into a fuel tank and is characterized by a single fuel line fluidly connected to a fuel rail. A returnless fuel system lacks a fuel return line from the fuel rail and is unable to circulate fuel between the fuel rail and fuel tank, thus eliminating fuel heating and weathering.
A fault in a returnless fuel system may result in replacement of the returnless fuel system during service. Information determined during on-board operation of the returnless fuel system may assist in determining a root cause of such a fault.